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Related papers: LOFAR observations of galaxy clusters in HETDEX

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Massive merging galaxy clusters often host diffuse Mpc-scale radio synchrotron emission. This emission originates from relativistic electrons in the ionized intracluster medium (ICM). An important question is how these synchrotron emitting…

Large-scale diffuse radio emission is observed in some clusters of galaxies. There is ample of evidence that the emission has its origin in synchrotron losses of relativistic electrons, accelerated in the course of clusters mergers. In a…

Astrophysics · Physics 2009-11-13 M. Hoeft , M. Brueggen , G. Yepes , S. Gottloeber , A. Schwope

We present the first multi-frequency analysis of the candidate ultra-steep spectrum radio halo in the galaxy cluster PLCKESZ G171.94$-$40.65, using the upgraded Giant Metrewave Radio telescope (uGMRT; 400 MHz), and Karl G. Jansky Very Large…

The goal of the present study is to extend our current knowledge of the diffuse radio source (halo and relic) populations to $z$ $>$ 0.3. Here we report GMRT and EVLA radio observations of six galaxy clusters taken from the MAssive Cluster…

Astrophysics of Galaxies · Physics 2016-11-23 Viral Parekh , K. S. Dwarakanath , Ruta Kale , Huib Intema

We present LOFAR High-Band Array (HBA) observations of the Herschel-ATLAS North Galactic Pole survey area. The survey we have carried out, consisting of four pointings covering around 142 square degrees of sky in the frequency range…

Massive galaxy clusters are the most violent large scale structures undergoing merger events in the Universe. Based upon their morphological properties in X-rays, they are classified as un-relaxed and relaxed clusters and often host (a…

Cosmology and Nongalactic Astrophysics · Physics 2016-12-02 M. Pandey-Pommier , J. Richard , F. Combes , A. Edge , B. Guiderdoni , D. Narasimha , J. Bagchi , J. Jacob

Radio halos are diffuse synchrotron sources on scales of ~1 Mpc that are found in merging clusters of galaxies, and are believed to be powered by electrons re-accelerated by the merger-driven turbulence. We present measurements of extended…

Cosmology and Nongalactic Astrophysics · Physics 2017-01-18 Martin W. Sommer , Kaustuv Basu , Huib Intema , Florian Pacaud , Annalisa Bonafede , Arif Babul , Frank Bertoldi

We present the results of 20 ksec Chandra observations for each of 5 radio galaxies in the redshift range 2.0 < z < 2.6. For 4 of the 5 targets we detect unresolved X-ray components coincident with the radio nuclei. From spectral analysis…

We present the astrometric identification of 80 known radio pulsars as unresolved continuum sources detected at 144 MHz in the second data release of the LOFAR Two-metre Sky Survey (LoTSS DR2), which covers 27% of the Northern hemisphere.…

High Energy Astrophysical Phenomena · Physics 2026-02-18 G. A. C. Rijkers , C. G. Bassa , J. R. Callingham , T. Shimwell

Faraday tomography observations with the Low Frequency Array (LOFAR) have unveiled a remarkable network of structures in polarized synchrotron emission at high Galactic latitudes. The observed correlation between LOFAR structures, dust…

Astrophysics of Galaxies · Physics 2024-07-03 F. Boulanger , C. Gry , E. B. Jenkins , A. Bracco , A. Erceg , V. Jelić , L. Turić

Some galaxy clusters show diffuse radio emission in the form of giant halos (GHs) on Mpc scales or minihalos (MHs) on smaller scales. Comparing VLA and XMM radial profiles of several such clusters, we find a universal linear correlation…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-18 Uri Keshet , Abraham Loeb

We aim at an unbiased census of the radio halo population in galaxy clusters and test whether current low number counts of radio halos have arisen from selection biases. We construct near-complete samples based on X-ray and…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-16 Martin W. Sommer , Kaustuv Basu

Mega-parsec scale radio sources in the form of halos and relics are often detected in dynamically disturbed galaxy clusters. Although they are associated with merger-induced turbulence and shocks, respectively, their formation is not fully…

An important aspect of the radio emission from galaxy clusters is represented by the diffuse radio sources associated with the intracluster medium: radio halos, relics and mini-halos. The radio halos and relics are indicators of cluster…

Astrophysics · Physics 2009-11-10 L. Feretti , C. Burigana , T. A. Ensslin

The knowledge of the origin and statistical properties of diffuse radio emission in galaxy clusters has appreciably improved thanks to the GMRT Radio Halo Survey, a project based on 610 MHz observations of clusters belonging to a…

Cosmology and Nongalactic Astrophysics · Physics 2011-02-10 Simona Giacintucci

Nonthermal emission observed in galaxy clusters provides a direct probe into the plasma physics of the intra-cluster medium (ICM) under extreme conditions. We report the first detailed analysis of the giant radio halo in the merging galaxy…

Cosmology and Nongalactic Astrophysics · Physics 2025-12-01 Ramananda Santra , Ruta Kale , Simona Giacintucci , Herve Bourdin , Rashi Jain , Andrea Botteon , Gianfranco Brunetti

The Low Frequency Array (LOFAR) Two-metre Sky Survey (LoTSS) is a sensitive, high-resolution 120-168 MHz survey split across multiple tiers over the northern sky. The first LoTSS Deep Fields data release consists of deep radio continuum…

We present a follow-up study focused on cluster-scale diffuse radio emissions in 115 galaxy clusters in the Southern sky, using full-resolution (7.8") and tapered low-resolution (15") images from the MeerKAT Galaxy Cluster Legacy Survey…

Context. Cosmic rays and magnetic fields are key ingredients in galaxy evolution, regulating both stellar feedback and star formation. Their properties can be studied with low-frequency radio continuum observations, free from thermal…

Galaxy clusters grow by a sequence of mergers with other clusters and galaxy groups. During these mergers, shocks and/or turbulence are created within the intracluster medium (ICM). In this process, particles could be accelerated to highly…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-27 R. J. van Weeren , H. J. A. Rottgering , M. Bruggen
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